thyroid cancer
...f the gland. Anaplastic tumors, though extremely rare, develop on either side of the thyroid gland and spread rapidly to other parts of the body. It account for only 2% of all thyroid cancers but is the fastest growing, and most aggressive thyroid cancer type (Thackery 1057). The aggressiveness of each type of thyroid cancer is different. There are four main stages in each of the types of thyroid cancer except for anaplastic cancer (Rubin 91). In the stage I of papillary and follicular thyroid cancer, the cancer is located only in the thyroid and may be found in one or both of the lobes. In stage II if the patients are younger than 45 years of age, the cancer has spread beyond the thyroid. But if the patient is older than 45 years of age, the cancer is only in the thyroid and is larger than 1 centimeter. In stage III, the cancer is usually found in patients older than 45 years of age and has spread outside of the thyroid or has spread to the lymph nodes but not outside of the neck. In stage IV, the cancer is again usually found in patients over the age of 45. It most likely has spread to other parts of the body such as the lungs or bones (Thackery 1058). Medullary thyroid cancer is quite uncommon. In stage I, the is located in one or both of the thyroid glands and is about 1 centimeter in size, but throughout the last three stages of medullary thyroid cancer, the tumor grows by 1-4 centimeters and continuously spreads to other parts of the body (Shin 93). There is no staging system for anaplastic cancer of the thyroid. This cancer is located in either of the lobes and spreads faster than any of the other types (Thackery 1058). The exact cause of thyroid cancer is not known but some risk factors have been identified. From the early 1950's to the late 1960's, thousands of children received radiation to treat acne and to reduce infection of the tonsils, adenoids and lymph nodes (Shin 419). It has been proven that radiation is a risk factor for thyroid cancer. Another risk factor is diets that are low in iodine. In parts of the world that have low iodine diets papillary and follicular cancers occur more frequently (Ruben 86). Other risks factors for thyroid cancer include patients with a family history of thyroid cancer. Approximately 7% of thyroid cancer is caused by alteration of a gene called the RET oncogene, which can be inherited (Thackery 1057). Symptoms are rare, and the lump is not usually painful. The lump that can be felt in the neck is the most frequent sign of thyroid cancer. Swelling of the lymph nodes are another symptom. Such symptoms could possibly be roughness or a slight change in the voice due to pressure from the tumor on the nerve connected to the voice box or, difficultly in swallowing or breathing due to a tumor obstructing the esophagus or trachea (Longe 3306). Most cases of thyroid cancer are found during a routine physical examination. If the gland appears to be enlarged, the physician may order further tests to diagnose or rule out cancer. These tests include: a CT scan or ultrasonography. The ultrasound uses high-frequency sound waves that are emitted and received by a transducer that is passed over the neck region. The sound waves penetrate the body, and by electronic readings, the sound waves are arranged on a computer screen into a picture image of the thyroid gland and any tumors (Thackery 1058). Another test used is the thyroid scan. A patient is given radioactive iodine to drink. After the iodine has been absorbed by the thyroid, the patient must lie on his or her back with the neck region positioned under a scanner. The information received by the scanner is then sent to a computer that displays a 2-dimensional image of the thyroid used to identify areas in the thyroid that do not absorb iodine normally (Surks 165). The most accurate diagnostic tool for thyroid cancer is biopsy. The test is done in a hospital operating room under a general anesthesia. A sedative is usually given by an injection about one hour before the procedure. A small incision is made in the neck, and either side of the thyroid or the entire lump is removed. The sample is sent to a laboratory to be examined. If thyroid cancer is detected, the thyroid is removed (Shin 420). There are basically four different types of treatments used on patients with cancer of the thyroid: surgery, radiation therapy, hormone therapy, and chemotherapy (Longe 3307). Each treatment is widely used in fight against thyroid cancer, but not all have the same results. Surgery is the most common treatment for thyroid cancer. Surgical removal is the usual treatment if the cancer has not spread to other parts of the body. A physician can remove the cancer by using one or several operations. A lobectomy removes only the side of the thyroid where the cancer is found. A near-total thyroidectomy removes the entire thyroid except for a small portion. A total thyroidectomy removes the entire thyroid, and a lymph node dissection removes lymph nodes in the neck that contain cancer (Surks 161). Another treatment is radiation therapy, which uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation for thyroid cancer may come from a machine outside of the body (external radiation therapy) or from drinking a liquid that contains radioactive iodine. Radioactive iodine may be used in addition to surgery in papillary and follicular thyroid cancers. Because the thyroid absorbs the iodine, the radioactive iodine collects in any thyroid tissue remaining in the body and kills the cancer cells (Shin 415). Hormone therapy is another type of treatment which uses hormones to stop cancer cells from growing....